What is the term for the heart's relaxation phase?

The relaxation phase of the heart is known as diastole. During diastole, the heart chambers, particularly the atria and ventricles, relax and fill with blood. This phase is crucial for allowing the heart to receive blood returning from the body and lungs, ensuring that it has enough volume to pump effectively during the subsequent contraction phase, known as systole.

In contrast, systole refers to the phase of the heartbeat where the heart muscles contract, pumping blood out of the chambers. Cardiac output is a broader term that describes the volume of blood the heart pumps per minute, while heart rate refers to the number of times the heart beats in a minute. Understanding these phases and terms is essential for grasping how the cardiovascular system functions efficiently to maintain circulation and meet the body's oxygen demands.